Structural optimisation for minimising weight and welding in confined shipbuilding spaces: Enhancing safety and reducing costs

The increasing demands for reduced weight and lower carbon emissions in modern shipbuilding necessitate advanced structural optimisation techniques, particularly within the challenging context of confined manufacturing spaces. Numerous studies on ship structural optimisation have focused on achieving lighter designs, primarily by increasing the number of stiffeners while reducing the thickness of base plates. However, such approaches often lead to higher production complexity, extended fabrication time, and increased costs, especially when introducing new stiffener types. Moreover, welding in confined spaces presents significant challenges related to worker safety and project scheduling. This research proposes a structural optimisation approach that not only minimises structural weight but also reduces the extent of welding required during assembly. A multi-objective genetic algorithm (MOGA) integrated with a response surface methodology and constraint rules classification is employed. The optimisation variables include plate thickness, stiffener thickness, and stiffener dimensions, while maintaining a constant number of stiffeners to avoid additional welding operations. The results demonstrate that stiffened ship panels can be optimised to achieve lighter structures with reduced welding paths, particularly on web plates, thereby enhancing safety and lowering production costs in confined shipbuilding environments.